The heavy snow and intense cold of November and December 1995 promoted the formation of ice in the St. Lawrence Seaway. At the time of this occurrence, the concentration of ice was estimated at 10/10 grey ice. According to the Sailing Directions for the Great Lakes, navigation is considered difficult where the ice concentration is 7/10 to 9/10. The current in the Lac St. Franois channel sets fair with the channel, and its rate increases to two knots upstream of the entrance to the Beauharnois Canal. The weather conditions recorded on board the vessel show that visibility was restricted by snow. The south-west wind was blowing at between 25 and 35 knots, and the air temperature was minus 8C. Once she had entered the section of the channel between the Saint-Zotique anchorage and the Beauharnois Canal, the KAPITONAS MESCERIAKOV was no longer able to return to the Saint-Zotique anchorage or to stop because of the ice. The position of the KAPITONAS MESCERIAKOV and the prevailing environmental conditions made it very difficult to prevent the vessel from drifting toward the north edge of the channel.Analysis The heavy snow and intense cold of November and December 1995 promoted the formation of ice in the St. Lawrence Seaway. At the time of this occurrence, the concentration of ice was estimated at 10/10 grey ice. According to the Sailing Directions for the Great Lakes, navigation is considered difficult where the ice concentration is 7/10 to 9/10. The current in the Lac St. Franois channel sets fair with the channel, and its rate increases to two knots upstream of the entrance to the Beauharnois Canal. The weather conditions recorded on board the vessel show that visibility was restricted by snow. The south-west wind was blowing at between 25 and 35 knots, and the air temperature was minus 8C. Once she had entered the section of the channel between the Saint-Zotique anchorage and the Beauharnois Canal, the KAPITONAS MESCERIAKOV was no longer able to return to the Saint-Zotique anchorage or to stop because of the ice. The position of the KAPITONAS MESCERIAKOV and the prevailing environmental conditions made it very difficult to prevent the vessel from drifting toward the north edge of the channel. The vessel was sailing in restricted visibility in severe ice conditions. The ice field to the south of the Lac St.Franois channel was pushed northward by the winds. Once she had entered the channel, the vessel was no longer able to return to the Saint-Zotique anchorage or to stop. The bridge watch tried to counteract the drift to keep the vessel in the middle of the channel. The vessel appears to have struck the north edge of the channel abreast of buoy D4, causing a crack in the No.3 port double-bottom tank.Findings The vessel was sailing in restricted visibility in severe ice conditions. The ice field to the south of the Lac St.Franois channel was pushed northward by the winds. Once she had entered the channel, the vessel was no longer able to return to the Saint-Zotique anchorage or to stop. The bridge watch tried to counteract the drift to keep the vessel in the middle of the channel. The vessel appears to have struck the north edge of the channel abreast of buoy D4, causing a crack in the No.3 port double-bottom tank. The KAPITONAS MESCERIAKOV sustained damage when she was driven toward the north edge of the channel by ice. The pressure exerted by the ice on the sides of the hull hampered the vessel's efforts to return to the middle of the channel.Causes and Contributing Factors The KAPITONAS MESCERIAKOV sustained damage when she was driven toward the north edge of the channel by ice. The pressure exerted by the ice on the sides of the hull hampered the vessel's efforts to return to the middle of the channel.